Thread stitching machines have become known, to which printed sheets can be supplied both manually and automatically onto the stitching saddle. Thread stitching machines are known, to which folded printed sheets can be automatically supplied from a printing machine onto the stitching saddle.
A known thread stitching machine can be operated inline and/or offline. In this variant, the loading of the stitching saddle does not take place by means of an additional feed device, but laterally by means of an auxiliary saddle (horizontal loading). A digital printing machine or a folding machine, which places the folded and opened printed sheets directly on the auxiliary saddle, can be connected, for example, to the auxiliary saddle. A conveyor chain then transports the printed sheet to the stitching saddle, and a shoot-in roller or a transporting belt then conveys the printed sheet to the stitching saddle. In this case, only a plurality of printed sheets can be stitched one behind the other or individual signatures processed. A preliminary collection can take place on the auxiliary saddle, or unfolded signatures can be collected and then placed thereon. However, collected individual signatures coming from the digital printing machine can be guided onto the stitching saddle and stitched there.